You see it on TV, in magazines, and everywhere you turn, but few men know the dangers of taking testosterone.
Dr. Philip Werthman says when a man takes testosterone supplements, his brain thinks the body is making the hormone so natural production shuts down.
"After you start, this could potentially be a lifelong therapy," he said.
Patients can be left with side effects like lack of energy, loss of sex drive, and trouble focusing.
"Imagine how badly you felt when your testosterone was low that you wanted to go on therapy, now imagine when your testosterone's almost nonexistent," said Dr. Werthman.
Taking testosterone can also increase the risk of infertility, prostate cancer, liver problems, blood clots, heart attack and stroke.
"Brian," who doesn't want his real name used, took testosterone injections for two years. His doctor prescribed it, even though Brian's levels were normal.
"He said I think you can, you'll get some benefits. It's worthwhile. You should try it."
Brian went off the hormone when he found out it was making him infertile. He also lost his sex drive and suffered other side effects.
"I became very tired all the time. I couldn't focus. I would forget things," said Brian.
He is currently suing the doctor and wants others to know the dangers.
"If you get off of it, you may never be normal again, which is what seems to have happened to me," Brian said.
Testosterone comes as a pill, patch, gel and injection.
While there are cases where testosterone can help men who truly need it, Dr. Werthman believes it's often over-prescribed.
A recent study found 25% of men who were given testosterone never even had their levels checked.
Dr. Werthman said over-the-counter supplements can be just as damaging as those given in a clinic.
